The invention relates to re-closable flexible packages. More specifically the invention relates to flexible bags or pouches having an openable and re-closable fastener structure at its open end for reuse.

DESCRIPTION OF RELATED ART

Re-closable bags or packages are finding increasing use in various applications ^■ including packaging of fruits and vegetables, snacks, stationary, items of daily needs and the like. New applications are constantly being identified for such re-closable bags that allow a user to readily repack any product even after its primary packaging has been initially opened. Re-closable bags typically include a re-closable means such as a press to close zipper or slider zipper that is installed on the open end of the bag. The re-closable fastener structure is mounted on any one edge of the package at right angle to the adjacent edge.

With the large number of products that are now packaged in re-closable packages, the shapes and sizes of the products packaged also vary significantly. While conventionally shaped and sized bags and pouches are convenient for most products, they are often larger than the size required to accommodate some product shapes. This is particularly so in the case of products that may be referred to as "long" or having large length compared with their width. Examples of such products include pens, pencils, toothbrushes, chop sticks, straws, fork and spoons etc.

Figure 1 illustrates a schematic illustration of a conventional re-closable bag (10) having a re-closable fastener structure at the open end that is used to pack a long product. The fastener structure includes a zipper (20) and a slider (30) mounted on the zipper, such that movement of the slider from one end of the zipper to the other end closes the opening (40) of the bag. The width of the bag (X) is substantially larger than the width of the product (Y) to allow for the opening (40) to have a size through which the product may be conveniently removed. As the bag is sized larger than what is required to provide the required mouth opening, area (60) of the bag is effectively a waste.

To address this, re-closable bags or pouches as illustrated in figure 2 were proposed where the fastener structure (20) was mounted along the larger side of the bag and having a height sufficient for storing the product. Though, in this case, the bag wastage is reduced or possibly eliminated, the length and consequently cost of the re-closable fastener structure required increases significantly, thereby adversely affecting the cost of the bag.

There is therefore a requirement for re-closable bags for products, particularly long products, such that the bag may be sized appropriately for the product and does not require excessive length of the re-closable fastener structures.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The accompanying drawings illustrate the preferred embodiments of the invention and together with the following detailed description, serve to explain the principles of the invention.

Figure 1 illustrates a re-closable bag known in the art.

Figure 2 illustrates another type of re-closable bag known in the art.

Figure 3 illustrates a re-closable flexible package in accordance with an embodiment of the present invention.

SUMMARY

The invention relates to a flexible package comprising at least one flexible sheet configured to form a pair of side edges and a bottom edge; a diagonally oriented opening opposite to the bottom edge extending between the side edges; and a re-closable fastener structure at the opening of the package. DETAILED DESCRIPTION

To promote an understanding of the principles of the invention, reference will be made to the embodiment and specific language will be used to describe the same. It will nevertheless be understood that no limitation of scope of the invention is thereby intended, such alterations and further modifications in the illustrated device and such further applications of the principles of the inventions as disclosed therein being contemplated as would normally occur to one skilled in art to which the invention relates.

Flexible pouches, bags or packages are typically formed by either placing two sheets of flexible substrates or films, one above the other and sealing the edges on three sides to form a mouth having an opening or by folding a flexible web and sealing in the middle or one long edge and bottom edge, leaving top edge to form an open mouth. A re-closable fastener structure is attached to the mouth to open and close the flexible package opening.

The re-closable fastener structure typically includes a zipper closure comprising of two interlock spaceable fastener strips mounted on the edges of the flexible package sides, forming the mouth of the bag. The fastener strips can be of various configurations, e.g. interlocking ribs and groove elements having so-called male and female profiles, interlocking closure members having hook-shaped or ball-shaped closure profiles, etc.

In the case of slider zipper type re-closable fasteners, a slider is mounted on the zipper closure to facilitate its opening and closing by sliding across the length of the zipper. The movement of the slider toward one end result in the disengagement of the two sides of the zipper to open the mouth and the movement of the slider in reverse direction engages the two sides of the zipper to close the mouth. The slider is shaped to straddle the lockable profiles on the two sides of the zipper. In a straddling slider, the ends of the slider are open to allow the two zipper tracks to pass through. Alternately, a slider having separating finger may be employed. The slider can be made out of polymer or metal. The slider may be made in multiple parts and joined together by ultrasonic, heat or adhesive bonding or the parts may be constructed to be snapped together. The slider may also be of one-piece construction. The slider can be made using any desired method, such as injection molding, die casting, machining etc.

In another type of the zipper, there is no slider and the two tracks of the zipper get locked by pressing together and can be opened by pulling apart.

With reference to figure 3, a re-closable flexible package in accordance with an embodiment is illustrated. The figure illustrates a flexible package (100) formed of two flexible sheets (12) and (14) joined along the edges to form a bottom edge (22) and a pair of side edges (16) and (18). An opening (40) is formed at the top edge (24) of the flexible package. The top edge (24) is provided with a re-closable fastener structure for opening and closing the open end of the flexible package. The re-closable fastener structure includes a zipper closure (20) having a slider (30) mounted on it. The opening is diagonal and is made at a desired angle to have the opening longer than the width of the package. In the embodiment illustrated, the bottom edge is horizontally formed with the two side edges perpendicular to it. However, the bottom edge may also be diagonally formed such that the side edges are inclined to it. Any other profile can also be made at the bottom edge, as desired.

Alternatively, a single sheet of flexible material may be configured to form the flexible package by sealing the required edges.

In accordance with an aspect the diagonal opening is oriented at an angle between 120 degrees to 150 degrees from any one of the adjacent edges and preferably the diagonal opening is oriented preferably substantially at an angle of 135 degree from any one of the adjacent edges. The package sides may be made of paper or coated paper or laminated paper, one side or both sides, with polymer film or film laminates with multiple layers of different polymers or films. The layers can be unprinted, printed or metallized or having an aluminum foil as one of the layers. The polymers or thermoplastic material, such as low-density polyethylene, substantially linear copolymers of ethylene, a C3-C8 alpha olefin, polypropylene, polyvinylidene chloride, polyester, polypropylene laminated with other materials such as nylon, polyester and like materials or blend of two or more of these polymers.

The zipper closure may be made from any thermoplastic material. The slider can be molded from any suitable polymer, such as nylon, polypropylene, polystyrene, acetal, polyketone, polybutylene teraphthalate, high-density polyethylene, polycarbonate or ABS etc. The slider may be made of metal as well by die casting or any suitable machining process.

The preferred method of attaching the slider-zipper or press to lock zipper assembly to the opening of the package is by conventional heat sealing, where the surface of the zipper and/or the sheet is softened or melted by application of heat and pressure, the softened or melted material thereafter fuse the zipper and the sheet surfaces together when it solidifies upon cooling. If the package material is a laminate comprising, for example, a metallized thermoplastic material, with the layer of metal or paper being disposed on the exterior of the flexible package , then the zipper could be attached (i.e. joined) to the layer by any suitable means such as an adhesive layer, an adhesive bonding strip and so forth. The slider-zipper assembly may be attached to the opening of the flexible package by applying ultrasonic or high frequency energy.